Laptop Motherboard Diagnosis/Repair (Can't run on AC or recharge battery)

[sigfrid]

Hello everyone,

I have an old Dell inspiron 9300 that can no longer run on Adapter alone, nor recharge batteries, the LED doesn't wink when the AC is connected.
Here is the stupid thing that I've done to get to this condition, (please don't laugh at me . My power adapter cord was damaged so I decided to get a longer cord and solder it; but I did the stupid error of reversing the electrical wires of the charger and tried to run the laptop using that, and of course it didn't work!
However, the laptop was still running OK on battery alone, so I guess it's the charging circuit that was damaged. I don't it's the power jack or something like that...

Is there a way to get it working again with AC without having to replace the whole motherboard? Since it's an old laptop.

Thank you!

 

[jarotech]

We are talking about the wires between the adapter and the laptop, right. How many wire did you prolong between the adapter and laptop ?

 

[sigfrid]

We are talking about the wires between the adapter and the laptop, right. How many wire did you prolong between the adapter and laptop ?

Thanks for your answer!
yes we are talking about the wires between the adapter and the laptop. I used two wires like in here. But of course I reversed them

 

[jarotech]

On my schematic, 3 wires are coming from the adapter, DC-, DC+ and PWR ID. Maybe the PWR ID should be connected to the laptop, for recognize the adapter.

 

[sigfrid]

On my schematic, 3 wires are coming from the adapter, DC-, DC+ and PWR ID. Maybe the PWR ID should be connected to the laptop, for recognize the adapter.

Yes there are 3 wires in my adapter too, but it was already working great with 2 wires only. I have also tried with another brand new adapter (which used to work in the past) but it didn't work.

Also, I don't think it's the power jack, I remember I have tested it with a multimeter. I believe it's a fuse or something like that.

 

[jarotech]

OK, check the continuity of the coils, PL1 and PL2, the transformer PL3 between pins 1 and 4, and pins 2 and 3 for the continuity.

 

[sigfrid]

Hello again,


Sorry for the delay, I had to dismantle it again.

I can't find PL1 and PL3?
the two big coils are PL6 and PL7.

 

[jarotech]

No problem for the delay, I think that you have either PL1 and PL2 or just the transformer PL3. They should be around the DC jack, on the CPU side.

 

[siawosh]

hi guys...
i have same problem .. how can i fix that??
i have pl1 and pl2 , not pl3 ... (
pls help me

 

[jarotech]

hi guys...
i have same problem .. how can i fix that??
i have pl1 and pl2 , not pl3 ... (
pls help me

Hi, they remove the PL3 filter on 9/26/2005, so you don't have the filter on your motherboard.

 

[siawosh]

hi guys...
i have same problem .. how can i fix that??
i have pl1 and pl2 , not pl3 ... (
pls help me

Hi, they remove the PL3 filter on 9/26/2005, so you don't have the filter on your motherboard.

tanx u for replay...my english is not well but i hop you can help me to fix this
so can u help me witch on of these are my problem??
i have BEEB by multimeter on both side of "B" zone...
i changed that and fix the BEEB but when i plug Charger in, it's like frist Have BEEB...
can u help me if i change the IC and "B" can i repair that??
http/upload7.ir/images/66459545607868070575.jpg

 

[jarotech]

Hi, to check PQ3 or PQ4 just read the voltage on the capacitor PC7, you should have 19VDC. That will also check PL2 and PL21. But in the B zone, I don't know the number for the capacitor that you have encircle.

 

[siawosh]

Hi, i checked PC7 and PQ4 , both have 19vDC . so ok , For B zone the capacitor don't Have Number Just Color , so this picture is for back of the board , i have Checked PL1 , but one of Resistor (PR10) i chacked is not number on Resistor (number on the R is 1000 but i checked is around 3000-4000) , can PR10 Or PL1 are just my problem?
http/upload7.ir/images/76655560961995156462.jpg

 

[jarotech]

OK, you said you have the same problem as the OP, just to start from the right foot, tell me what are the problems you have with your laptop. You have a Dell Inspiron 9400 is that right.

 

[siawosh]

OK, you said you have the same problem as the OP, just to start from the right foot, tell me what are the problems you have with your laptop. You have a Dell Inspiron 9400 is that right.

yes, i have this problem , reversing the electrical wires of the charger and tried to run the laptop using that...
now i checked back of the board , i think PR10 or maybe PL1 is not normal , and CPU side of board i just have problem whit B zone , i chaged it and fixed , but when i plug charger in , again i have problem whit that...now i dont know whay!